1. FIELD OF THE INVENTION
This invention relates to turbine systems. In particular, this invention pertains to turbine systems including a power take-off in combination with a compressor rotor and a power turbine. More in particular, this invention is directed to a power producing constant speed turbine. Still further, this invention relates to a power producing constant speed turbine which utilizes a plurality of product of combustion streams passing in a helical manner through a multiplicity of longitudinally spaced and axially aligned turbine rotor discs. Further, this invention pertains to a power producing constant speed turbine where the rotor discs of the turbine are maintained in substantially constant speed responsive to the load applied to the turbine. Additionally, the instant invention relates to a power producing constant speed turbine wherein a plurality of nozzles emit products of combustion in a substantially tangential manner when taken with respect to an outer peripheral wall of the aligned rotor discs. Still further, the subject invention is directed to a power producing constant speed turbine that utilizes the concept of applying the centrifugal force in a radial outward direction which magnitude of such force is dependent upon the rotative speed of the rotors, against the radial force on the product of combustion gases radial inward force provided by the static pressure drop between the nozzles surrounding the rotor discs and exit passage formed longitudinally through the center of the axially aligned rotor discs.
2. DESCRIPTION OF THE PRIOR ART
In the past, single stage compressors used in combination with turbines have operated at a compression ratio of no greater than 5 to 1. In the present invention, a single stage centrifugal compressor is employed that is characterized by a number of diffuser tubes extending outwardly in spaced relationship from the rotor housing, with the tubes being arranged in first and second groups that are in communication with first and second volute casings. First and second combustion tubes extend from the first and second volute casings to the interior of a housing in which the turbine rotor is rotatably supported.
Due to the structure above-described, the single stage compression rotor, which is driven by the turbine rotor, produces air at a compression ratio of up to 25 to 1 in the combustion tubes in which burners are located. Hot gaseous products of combustion resulting from this compression ratio discharge to the turbine rotor at a temperature of between 2050.degree. to 3000.degree. F., and at high velocity. The turbine rotor is formed from a number of circular discs disposed in a side-by-side spaced relationship to define a number of circular passages therebetween. Gaseous products of combustion are subdivided into a number of streams within the interior of the turbine rotor housing and are directed tangentially onto the turbine rotor to enter circular passages defined between the discs. The turbine discs are generally circular or conical in overall contour and include an outer arcuately directed peripheral wall. The gaseous products of combustion are directed in a substantially tangential manner to the outer peripheral wall of the rotor discs. This allows the issuing products of combustion to have a high tangential velocity vector as opposed to a substantially low radial velocity vector. The centrifugal force applied to these issuing gases operation in an outward radial manner. Thus, with a rather low inward radial force, the outward centrifugal radial force which is dependent upon the rotary speed of the rotor discs, may be used to operate one against the other to provide a speed regulation mechanism.
When the load on the turbine system is increased, the turbine rotor discs tend to decrease in rotative speed, thus, the products of combustion radial inward force is increased to provide increasing frictional drag forces on the radial discs and such increases the rotative speed of the discs. In opposition, when the power take-off load is decreased, the rotative speed of the turbine rotor discs begins to increase thus, increasing the centrifugal force applied to the issuing gases. This tends to act on the gaseous products of combustion in an outward radial manner to drive such substantially external to the outer peripheral walls of the rotor discs. Less gaseous products are in frictional contact with the rotor discs and thus the frictional drag is reduced and the rotor discs begin to increase in rotative speed. The turbine discs are formed from high temperature metal or refractory material such as hot pressed silicon nitride that can withstand an operating temperature of 2500.degree. F.
By increasing the inlet temperature of the hot gaseous products of combustion to 350.degree. F. above the present operating temperature of 2000.degree. F., the horsepower output of the present invention may be doubled over the prior art turbines of the same size, and the thermal efficiency increased from 36 percent to approximately 43 percent.
The present turbine has the operational advantage that it has but one-tenth of the emissions of equivalent size internal combustion engines. The present invention has the further advantage that it is capable of burning any fuel such as powdered coal, residual oils, a wide variety of liquid fuels, as well as combustible gases.
In operation, the gaseous products of combustion enter the turbine housing through nozzles that are positionally located substantially tangential to an outer peripheral wall of the longitudinally aligned plurality of rotor discs. As has hereinbefore been described, the tangential position and emission of the combustion gases is important in that such allows the speed control of the turbine responsive to the load applied. In any case, the combustion gases travel in a helical manner through circular passages defined by adjacently spaced turbine discs and frictionally drive the discs in a rotative manner. As a result, the discs are not subject to a succession of rapidly applied pulses such as may occur in the operation of conventional bladed turbine rotors, and the discs of the present invention are not subject to combined bending stresses, but rather only shear and centrifugal tensile loads.
A major object of the present invention is to provide a power producing rotary turbine that is capable of reducing exhaust emissions by a factor of ten relative to present day internal combustion engines, is compact and capable of producing a high power output relative to the weight and size thereof, and one that operates with substantially increased thermal efficiency relative to prime movers of prior art design.
Another major object of the present invention is to provide a substantially constant speed turbine system which permits the rotor discs of the turbine to maintain substantially constant speed responsive to the load applied to the turbine system. In this manner, substantial amounts of hardware are not required and further additional control systems are obviated to maintain the rotor discs operating at substantially constant speed. In prior art designs, such speed regulation has involved complex hardware and electronic system designs which have increased the capital expenditures as well as reducing the reliability of such systems. By providing an automatic system utilizing physical principles applied by predetermined positional locations of various elements within the systems, a constant speed system responsive to the load in an automatic fashion has now been achieved.